As states gear up for the Affordable Care Act, they're trying to figure out if there will be enough providers of health care to meet demand from the newly insured.

California is one of 15 states expected to consider legislation this year that would give advanced practice nurses more authority to care for patients without a doctor's supervision.

Tina Clark is a nurse practitioner at Glide Health Services, a clinic in San Francisco's Tenderloin district, a low-income section of the city.

Anastacia Casperson, who has struggled with homelessness and drug addiction, came to the clinic because she was alarmed about swelling in her legs. Clark spends a half-hour with Casperson, gives her a prescription for a diuretic and talks to her about quitting smoking. Casperson says she's been coming to this clinic for a few years.

"They have compassion for a client. They have understanding for a client," Casperson says. "I like the nurses here because they're like one big family, and they all work together."

Glide is run by nurses with advanced training. Even under current law, nurse Clark can see patients without a doctor in the room. But a physician visits the clinic 12 hours a week to sign forms and consult on difficult cases.

"Nurses and nurse practitioners are a very, very important part of the health care team, but they are part of a team," says Dr. Paul Phinney, president of the California Medical Association.

Phinney's group is opposed to allowing more independence for nurses. He says they are an important part of the health care team, but they don't have as much training, and may not know as much about testing and technology.

Plus, he says, there's nothing in the bill that would require the empowered nurses to go where they are needed most.

"I would be very surprised if should this bill pass that all of a sudden you'll see a massive egress of nurse practitioners out into medically underserved areas. I just don't see that happening," he says.

But University of California, San Francisco, health care economist Joanne Spetz says research shows otherwise.

"Nurse practitioners are more likely to practice in settings that serve large shares of Medicaid patients, and they're somewhat more likely to practice in rural communities," Spetz says.

Nurse practitioners can be trained much more quickly than a physician, and their compensation is lower, Spetz points out.

"So when a legislature is looking at the insurance of hundreds of thousands of people and the demand for care that those people are going to have, getting health professionals to meet their needs as quickly as possible and as cost-effectively as possible is a real need," she says.

The next step for the California bill on nurses is a hearing Monday in the state Senate Appropriations committee.

This piece is part of a partnership between NPR, Capital Public Radio and Kaiser Health News.

State governments are preparing for next year, when much of the new federal health care law, the Affordable Care Act, takes effect. Among other things, they are considering redefining the roles of some health care professionals. Many states have or will be considering measures to give advanced practice nurses, or nurse practitioners, more independence. Such an effort in California is already stirring up political tensions between doctors and nurses. Pauline Bartolone from Capital Public Radio reports.

PAULINE BARTOLONE, BYLINE: Some nurse practitioners in California already see patients without a doctor in the room. Patients like Anastacia Casperson.

ANASTACIA CASPERSON: My legs and my feet are swollen.

TINA CLARK: Hmm. When did that start?

CASPERSON: Last night.

BARTOLONE: Casperson has struggled with homelessness and drug addiction. Now she's at Glide Health Services, a clinic in a low-income area of San Francisco called the Tenderloin. Her nurse, Tina Clark, spent a half hour with her.

BARTOLONE: Casperson never saw a doctor, and left with a prescription for a diuretic. She's perfectly happy getting care from nurses.

CASPERSON: They have compassion for a client. They have understanding for a client. I like the nurses here. Because they're like one big family and they all work together.

UNIDENTIFIED WOMAN: So we're going to wait for her results to come back and then...

BARTOLONE: This clinic is run by nurses with advanced training. Nurse practitioners in California have at least a Masters level education. A physician does spend 12 hours a week at the clinic, signing forms and consulting on difficult cases. Right now California law says nurses must follow procedures set after consulting a doctor. But lawmakers are considering eliminating that requirement. And that idea doesn't sit well with some doctors.

DR. PAUL PHINNEY: Nurse practitioners, although they can be very good at what they do, won't have the training to consider as wide a range of diagnoses.

BARTOLONE: Dr. Paul Phinney is president of the California Medical Association. His group is strongly opposed to allowing more independence for nurses. He says they are an important part of the health care team, but they don't have as much training and may not know as much about testing and technology.

PHINNEY: It's about patient safety and quality of care. As we move forward with the Affordable Care Act, it's going to be very important that we develop teams of all kinds of health professionals to work together in new ways to provide that care.

BARTOLONE: Phinney also questions whether the law would fulfill its purpose; to help make sure there's primary care in areas that need it, like inner cities and rural counties.

PHINNEY: I would be very surprised if, should this bill pass, that all of a sudden you'll see a massive egress of nurse practitioners out into medically underserved areas.

BARTOLONE: Not so, says University of California San Francisco health economist Joanne Spetz.

JOANNE SPETZ: Nurse practitioners are more likely to practice in settings that serve large shares of Medicaid patients, and they're somewhat more likely to practice in rural communities.

BARTOLONE: Spetz says nurses can be trained much more quickly than a physician and their compensation is lower.

SPETZ: So when a legislature is looking at the insurance of hundreds of thousands of people, getting health professionals to meet their needs as quickly as possible and as cost-effectively as possible is a real need of legislatures.

BARTOLONE: Fifteen states this year have or are expected to put forward bills to loosen laws for advanced nurses. That's double what it was last year. For NPR News, I'm Pauline Bartolone in Sacramento.

GREENE: And Pauline's story is part of a collaboration among NPR, Capital Public Radio, and Kaiser Health News. Transcript provided by NPR, Copyright NPR.